Tensionless hitch

[Dan@JBT]

For tying off branches for rigging I have been told that I should stop doing 2 half hitches and clipping a carabiner and instead do this as it is "3 times quicker and 5 times stronger"... from what I've read it's general application is on a fixed anchor for rappelling... as the anchor doesn't move, the friction against the anchor takes the load and the carabiner doesn't come in to play (so strength is retained). For rigging however I would think as the load rotates from being cut free the force from the load would act on the carabiner and create an undesirable bend radius and significant strength loss in the rope... does anyone have any experience with this hitch... or have you seen something in a knot book...

Thanks

Dan

 

[Magnum783]

It makes sense but I do
See where there could be some serious problems. What is the rest of the populous opinion before I comment and reveal I have missed something as I am sure I did.

 

[Del_]

I'll be sticking with a running bowline and a marl thank you very much.

 

[BC WetCoast]

I find it hard to understand how the rope actually works on the high strength, but I think after the branch twist and turns on its way down, it's going to cinch in tight and make the groundie's job of untying it difficult.

Unless you're planning on rigging large branches or stem wood with the caribiner, I don't think the bend radius is really a factor. If I was rigging that large a piece of wood, where I'm nearing the working load capacity of my rope, I would be using a knots and not shock loading a caribiner.

 

[RajElectric]

Tensionless hitch has it's place, rare in treework IMHO.

 

[pdqdl]

I'll be sticking with a running bowline and a marl thank you very much.

Yep, although I generally prefer a timber hitch behind that "marl".

If you are tying to a rigid, immobile post/branch/whatever, feel free to use the tensionless hitch. Just make sure that it can take whatever torque you will be applying with the rope.

If you think for a moment that it is tensionless once it is a heavy branch hanging on a rope, then you are mistaken. It will unwind until the carabiner end is carrying 50% of the load, exactly what you were trying to avoid. Whoever told you that the tensionless hitch should be used to lower branches was ill-informed and not to bright about physics, either. Twenty wraps wouldn't change the 50% load on the carabiner if it is on a hanging branch.

The tensionless hitch only works because it is converting the line tension into a force perpendicular to the radius of the circular structure it is tied to, thereby applying a large amount of torque to the post it is tied to. Example: you intend to tie-off a 1000lb load to a one foot diameter post. You will be applying 1000 foot-pounds of torque to the post, potentially screwing it loose in the ground.

I tied just such a knot on a walnut tree once when I was using my 3/8" Amsteel rope on the crane-winch to pull it out of the mud-pit it was stuck in. What happened was that we stripped all the bark off a 14" diameter tree at every point that the rope was touching the tree: 7 full wraps. It took 12 wraps before we could hold the load applied by the winch, and we killed the tree in the process. Needless to say, our customer was not pleased.

 

[pdqdl]

One last comment: If you are really worried about breaking the rope, you can always use the Stilson hitch. It will never bind down, and it is little more than several half-hitches wrapping around the trunk onto the same rope. This will distribute some of the load at the first marl so it will be technically stronger than than the single half-hitch you were using...but not by much.

By the way Del, I'll bet you are tying half-hitches rather than a full marl. Small difference in strength, but they sure untie different.

 

[Del_]

One last comment: If you are really worried about breaking the rope, you can always use the Stilson hitch. It will never bind down, and it is little more than several half-hitches wrapping around the trunk onto the same rope. This will distribute some of the load at the first marl so it will be technically stronger than than the single half-hitch you were using...but not by much.

By the way Del, I'll bet you are tying half-hitches rather than a full marl. Small difference in strength, but they sure untie different.

Yes, I'm tying half hitches.

 

[DR. P. Proteus]

The marl is best used for cake boxes.

 

[Pelorus]

Or tying your shoelaces.

 

[pdqdl]

...or daisy-chained down a long dead branch that is likely to break into pieces when you cut it off.

 

[jefflovstrom]

What ever happened to the 'clove hitch' backed up by a 'half hitch'?
Jeff

 

[TheJollyLogger]

A clove can bind up under load a bit much for me.

 

[pdqdl]

Clove hitch can unroll a bit and lose holding strength. Not so with the timber hitch, which is easier to tie and holds much better.

Each knot has it's best usage. There are times when a timber hitch isn't so good an idea, either.

 

[BC WetCoast]

Clove hitch is better than a timber hitch on smaller branches. You need a fair size piece to make the timber hitch work properly.

 

[jefflovstrom]

The half hitch after the clove hitch makes it easier,, otherwise,, put two half hitches after the clove,,,
Jeff

 

[pdqdl]

Clove hitch is better than a timber hitch on smaller branches. You need a fair size piece to make the timber hitch work properly.

I have never seen a branch so small my timber hitch didn't hold. I got nothing against a clove hitch; it's just not my habit to use it. I have seen quite a few trunk sections where it was quite difficult to tie the timber hitch on without a lot of tracking around the tree.

I do use the clove hitch an awful lot in other places: two half-hitch knot, anchor bend, Buntline hitch.

 

[Pelorus]

I have never seen a small branch that I wanted to tie off with a timber hitch.
Steel biner preceded with a half hitch.
Some of you guys must be paid by the hour not the job.

 

[pdqdl]

I guess it all depends on what you call "small". Myself, I tie a timber faster than a clove, and I can guarantee that most groundies can untie them faster. Timber hitch unloaded comes loose real easy.

Light stuff, I am just as likely to put a 'biner on it and skip the 1/2 hitch. 30 years, and I have never broken a rope or a rigging tool on anything light, so I must not be doing it too badly.

I had to repair a stone wall on a 4' diameter trunk section that broke it's rope, but I didn't have that rigged right anyway. That was before the internet and higher learning...back when I had to figure everything out for myself.

 

[Pelorus]

"small" as in "big" enough to require 3 wraps of 5/8" StableBraid on a H2 (Hobbs lowering device)!!!
Will try to get some photos up next week.
I had an (old and tired) endless loop runner break years ago when speed lining something way too heavy........made a beautiful hole in the owner's cedar deck that we got to repair.